• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.78-80
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• 2014

Silicone structural glazing (SSG) is a method utilizing a silicone adhesive to attach glass, metal, or other panel material to the structure of a building. Windload and other impact loads on the facade are transferred from the glass or panel through the silicone structural sealant to the systems' framework. Silicone structural glazing systems are currently a very common method of glazing throughout the world. Locally, structural silicone glazing has become very common to achieve aesthetically pleasing and high utilization of small land for both residential and commercial building. Although structural silicone glazing has been utilized for approximately thirty years in Korea, the understanding of its technology was low and limited. Consequently, Korean projects experienced many quality issues during assembly and construction, even in very recently finished buildings. Adhesion loss and water infiltration occurred on more than one project, and the time and cost to repair these issues were substantial. In general, there are two kinds of structural silicones depending on fabrication methods. 1part structural silicone is for site glazing system and 2part structural silicone is for unitized factory glazing system. In this paper, 2part structural silicone which is very common for factory fabricating curtainwall systems was evaluated with regards to various mixing ratio. Since the structural performance of 2part sealant can be affected by mixing ratios, some extra ranges of recommended mixing ratio were evaluated to see any performance differences. Besides on cure profile, comparative evaluations for mechanical properties and adhesion develop on common building substrates were conducted.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.49.2-49.2
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• 2010

Polycrystalline CdTe thin films for solar cell continues to be a promising material for the development of cost effective and reliable photovoltaic processes. The two key advantages of this material are its high optical absorption coefficient and its near ideal band gap for photovoltaic conversion efficiency of 1.4-1.5 eV. In this study we made the CdTe thin films for solar cell application which was deposited on the glass substrates using a modified chemical spray method at low temperature. This process does not require the sophisticated and expensive vacuum systems. The prepared CdTe films were characterized with the aid of scanning electron microscope (SEM), UV-visible spectrophotometer, and X-ray diffraction spectrometer (XRD). Following are results of a study on the "Human Resource Development Center for Economic Region Leading Industry" Project, supported by the Ministry of Education, Science & Tehnology(MEST) and the National Research Foundation of Korea(NRF).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.217-221
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• 2003

This study proposes a new classification system and analysis methodology for time delay risk of apartment projects. And this study proposes the classification of major trades and risk level and risk index by performing expert-oriented interview and survey report on a national scale. The purpose of this study is to present basic data for time delay risk management system through the analysis of risk level, risk index and rank of major 5 trades(earth work, structure work, masonry work, window and door/glass work, and interior finish work) in apartment projects.

• Journal of Korean Association for Spatial Structures
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• v.20 no.1
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• pp.61-67
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• 2020

In the era of the Fourth Industrial Revolution, Various attempts are being made to converge new industries with IT industry to find new growth engines in the field of IT, maximizing efficiency in terms of productivity. 3D printers are also related to this, and various studies have been conducted worldwide to utilize them in the construction industry. At present, there is an active effort to study atypical structures using 3D printers. The most widely used method is the use of glass panels, however, the additional cost of the manufacturing process and thus the overall project cost cannot be ignored. In addition, the construction of the curvature of the existing two-way curved surface in the conventional flat joint method is not suitable for implementing an amorphous shape. In this paper, we propose an optimized shape through Abaqus analysis of various shapes of Space Truss interior using 3D printing technology using polymer.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.53-61
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• 1996

A clear understanding of the surface formation mechanism due to cutting is very important to help produce a good quality surface. Much of the roughness along the length of a bar being cut in a lathe can be explained in terms of macroscopic tool shape and feed rate. However, the roughness along the direction of cutting requires a different explanation. The formation of surface roughness is a problem in flow and fracture of materials in the vicinity of the tool edge. On a microscopic scale the cutting edge is rounded because it is impossible to grind a perfectly sharp cutting edge. Even if a perfectly sharp cutting edge were obtained it would soon become dull as a result of rapid breakdown and wear of the cutting edge. A research project is proposed in which in the main object is to model the surface formation mechanism due to cutting. The tool was assumed to be dull, that is, its edge has a finite radius. In order to study the effect of the radius of cutting edge on the surface formation, tools having different cutting edges were used. For orthogonal cutting experiment, cast iron and glass were chosen as brittle materials. Plowing forces acting in the cutting edge were estimated and its effect on the surface roughness was studied by observing the machined surface using optical microscope.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.113-126
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• 2004

연구목적 : 이번 실험의 목적은 외과적으로 형성된 성견의 1면 골내낭에 새롭게 제조된, Ca/P 비율이 0.6인 비결정성 calcium phosphate를 적용하였을 때 치주조직의 재생에 미치는 영향을 평가하는 것이다. 연구방법 : 6마리 성견의 양측 하악 제2소구치의 원심면, 제4소구치의 근섬면에 외과적으로 1면 골내낭을 형성하여 치은박리소파술을 시행한 부위를 대조군으로, calcium phosphate만을 이식한 부위를 실험 1군, calcium phosphate와 GTR을 동반한 부위를 실험 2군으로 설정하고 실험하여 술 후 8주에 치유결과를 조직학적으로 관찰하였다. 결론 : 1. 접합상피의 치근단 이동은 대조군에서 결손부 깊이의 30.90 ${\pm}$ 9.92%, 실험 1군에서 결손부 깊이의 24.08 ${\pm}$ 9.12%, 실험 2군에서 결손부 깊이의 38.68 ${\pm}$ 12.22%로 나타났으며 대조군과 실험 1,2군간에 통계적 유의차는 없었다. 2. 결합조직 유착은 대조군에서 결손부 깊이의 36.38 ${\pm}$ 9.03%, 실험 1군에서 결손부 깊이의 26.96 ${\pm}$ 4.24%, 실험 2군에서 결손부 깊이의 27.87 ${\pm}$ 9.70%로 나타났으며 대조군과 실험 1,2군간에 통계적 유의차는 없었다. 3. 신생백악질 형성은 대조군에서 결손부 깊이의 32.92 ${\pm}$ 10.51%, 실험 1군에서 결손부 깊이의 49.16 ${\pm}$ 12.70%, 실험 2군에서 결손부 깊이의 39.62 ${\pm}$ 12.14%로 나타났으며 대조군과 실험 1군간에 통계적 유의차가 있었다. 4. 신생골 형성은 대조군에서 결손부 깊이의 27.24 ${\pm}$ 7.49%, 실험 1군에서 결손부 깊이의 43.51 ${\pm}$ 13.34%, 실험 2군에서 결손부 깊이의 36.47 ${\pm}$ 15.11%로 나타났으며 대조군과 실험 1, 2군간에 통계적 유의차는 없었다. 이상의 결과에서 볼 때, calcium phosphate glasses는 신생골 형성에는 통계적으로 유의차는 없었지만 상당히 증가된 양상을 보였고 신생백악질 형성에는 크게 기여함을 알수 있었다.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2001.10a
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• pp.61-86
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• 2001

All cancers are caused by abnormalities in DNA sequence. Throughout life, the DNA in human cells is exposed to mutagens and suffers mistakes in replication, resulting in progressive, subtle changes in the DNA sequence in each cell. Since the development of conventional and molecular cytogenetic methods to the analysis of chromosomal aberrations in cancers, more than 1,800 recurring chromosomal breakpoints have been identified. These breakpoints and regions of nonrandom copy number changes typically point to the location of genes involved in cancer initiation and progression. With the introduction of molecular cytogenetic methodologies based on fluorescence in situ hybridization (FISH), namely, comparative genomic hybridization (CGH) and multicolor FISH (m-FISH) in carcinomas become susceptible to analysis. Conventional CGH has been widely applied for the detection of genomic imbalances in tumor cells, and used normal metaphase chromosomes as targets for the mapping of copy number changes. However, this limits the mapping of such imbalances to the resolution limit of metaphase chromosomes (usually 10 to 20 Mb). Efforts to increase this resolution have led to the "new"concept of genomic DNA chip (1 to 2 Mb), whereby the chromosomal target is replaced with cloned DNA immobilized on such as glass slides. The resulting resolution then depends on the size of the immobilized DNA fragments. We have completed the first draft of its Korean Genome Project. The project proceeded by end sequencing inserts from a library of 96,768 bacterial artificial chromosomes (BACs) containing genomic DNA fragments from Korean ethnicity. The sequenced BAC ends were then compared to the Human Genome Project′s publicly available sequence database and aligned according to known cancer gene sequences. These BAC clones were biotinylated by nick translation, hybridized to cytogenetic preparations of metaphase cells, and detected with fluorescein-conjugated avidin. Only locations of unique or low-copy Portions of the clone are identified, because high-copy interspersed repetitive sequences in the probe were suppressed by the addition of unlabelled Cotl DNA. Banding patterns were produced using DAPI. By this means, every BAC fragment has been matched to its appropriate chromosomal location. We have placed 86 (156 BAC clones) cytogenetically defined landmarks to help with the characterization of known cancer genes. Microarray techniques would be applied in CGH by replacement of metaphase chromosome to arrayed BAC confirming in oncogene and tumor suppressor gene: and an array BAC clones from the collection is used to perform a genome-wide scan for segmental aneuploidy by array-CGH. Therefore, the genomic DNA chip (arrayed BAC) will be undoubtedly provide accurate diagnosis of deletions, duplication, insertions and rearrangements of genomic material related to various human phenotypes, including neoplasias. And our tumor markers based on genetic abnormalities of cancer would be identified and contribute to the screening of the stage of cancers and/or hereditary diseases

• The Journal of Advanced Prosthodontics
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• v.11 no.1
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• pp.7-15
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• 2019

PURPOSE. The aim of this study was to identify the effects of three aesthetic restorative materials on the wear between tooth and restoration by a pin-on-disk manner. MATERIALS AND METHODS. Six aesthetic restorative materials were used to prepare disk specimens for wear test, which were Lava Zirconia as zirconia group, Vintage MP and Cerabien ZR as veneering porcelain group, Gradia Direct microhybrid composite containing prepolymerized fillers, Filtek Z250 microhybrid composite containing zirconia glass and colloidal silica particles, and Filtek Z350 nanocomposite as composite resin group. Vertical loss of the worn cusp, change of the surface roughness of the restoration materials, and the surface topography were investigated after wear test under 9.8-N contact load. RESULTS. The porcelain groups (Vintage MP and Cerabien ZR) caused the largest vertical loss of teeth when compared with those of the composite resin and zirconia groups, and Filtek Z250 microhybrid composite results in the second-largest vertical loss of teeth. The surface of Filtek Z350 nanocomposite was deeply worn out, but visible wear on the surface of the zirconia and Gradia Direct microhybrid composite was not observed. When the zirconia surface was roughened by sand-blasting, vertical loss of teeth considerably increased when compared with that in the case of fine polished zirconia. CONCLUSION. It was identified that microhybrid composite resin containing a prepolymerized filler and zirconia with reduced surface roughness by polishing were the most desirable restorative materials among the tested materials to prevent the two-body wear between aesthetic restorative material and tooth.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.162-170
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• 2004

On the basis of the radiotracer technology and the related equipments which have been developed for its industrial application through the nuclear long-term research project, a radiotracer study on sediment transport was carried out as a part of the development of the radiotracer technology for a coastal environment. The crystalline material doped with iridium having a similar composition and specific gravity as those of the bedload sand collected from the research area was produced by the oxide-route method. A radioisotope container was specially designed to inject the radiotracer from 1 m above the sea bedload without radioactive contamination during the transport from the nuclear reactor at KAERI. The position data from the DGPS and the radiation measurement data were collected concurrently and stored by means of the application software programmed with the LabVIEW of the National Instrument. The position data was reprocessed to represent the real position of the radiation probe under water and not that of the DGPS antenna on board. The time dependency of the spatial distribution of the sediment was studied in the area through three tracking measurements after the iridium glass was injected. This trial application showed the potential of the radiotracer technology as an important role for maintaining and developing the coastal environment in the future.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.439-455
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• 2003

연구목적 : SLA surface dental implant 주위의 3면 골내낭에서 xenogeneic demineralized bone matric putty, porous ${\beta}$-tri-calcium phosphate, 새로이 개발된 non-crystalline calcium phosphate glass를 사용한 치료를 조직학적으로 비교 평가하기 위한 것이다. 연구방법 : 실험동물로는 15개월에서 18개월 사이의 12kg에서 15kg 정도되는 성견을 사용하였다. 20개의 SLA surface implant가 사용되었으며, 성견 하악의 양측에 각각 2개씩 사용되었다. 임플란트 식립전에, 각각의 임플란트 근심면에 straight fissure bur를 이용하여 표준화된 3면 골내앙(근원심 5mm ${\times}$협설 3mm ${\times}$깊이 3mm)을 형성하였다. 형성된 골 결손부에는 demineralized bone matrix putty, porous ${\beta}$-tri-calcium phosphate, non-crystalline calcium phosphate glass를 넣은 것을 각각 실험군으로, 이식재를 넣지 않은 것을 대조군으로 사용하였다. 8주 후에 실험 동물을 희생시키고 조직학적 관찰을 하였다. 결과 : 조직학적 소견상 임플란트 주위에 급성 염증 소견은 보이지 않았으며, non-crystalline calcium phosphate glass은 매우 적은량의 신생골을, ${\beta}$-TCP을 이용한 골내낭에서는 약간의 기저부에서 유래된 신생골이 관찰된다. ${\beta}$-TCP granules 가운데로 상당량의 측면의 골에서 유래된 신생골 형성이 보인다. xenogeneic DBM putty에서는 많은 량의 신생골이 기저부에 형성된 것을 볼수 있으나 대조군과의 차이는 크지 않다. 이식재의 종류와 상관없이 흡수되지 않은 이식재를 임플란트 주위에서 관찰할 수 있었다. 골내낭 안의 이식재들은 모두 connective tissue로 둘러 싸여 있었다. 모든 실험군에서 이식재에서 기인한 신생골 형성과 임플란트 표면에 신생 골유착의 조직학적 증거는 발견되지 않았다.